Motion converter



H. F. VACHE MOTION CONVERTER April 10, 1951 Filed May 22 1948 3 Sheets-Sheet 1 IN EN 0R. flm y E ac e flfim s April 10, 1951 H. F. VACHE MOTION CONVERTER 3 Sheets-Sheet 2 Filed May 22, 1948 April 10, 1951 H. F. VACHE MOTION CONVERTER 3 Sheets-Sheet 5 Filed May 22, 1948 Patented Apr. 10, 1951 UNITED STATES A The present invention relates to a certain new and useful instrument for converting rotary motion into reciprocating or oscillating motion.

- An object of thepresent invention is to provide a small, portable and convenient instrument to be used with a source of rotary power, thereby to impart an oscillating motion to a tool-holder and tool supported in said holder with a, minimum of effort by the user of the present invention Another object of the present invention is to provide an integral unit containing an electric motor, or similar rotary power unit, and a converter for changing the rotary motion to reciprocating motion.

In the'past there have been shown various methods and means of converting circular or rotary motion so as toimpart an oscillating or reciprocating. motion to a driven instrument.

However, these tools or machines have been, for the most part, cumbersome and heavy and complicated in their construction and operation, It is contemplated that this invention will provide a light-weight, inexpensive and easily-operated, easily transported instrument which will provide the user with a rapidly-oscillating power tool. Thus it is contemplated that the user of the present invention will have available a convenient small-siz power-driven tool-holder to which he can attach a file, saw, rasp, sandpaper, emery cloth, bufier or similar tool which requires reciprocating motion for its use. This instrument 4 Claims. (01. Pi-57) ATENT orece 1 V is adapted to fit inside the rotatable cam-track member in such manner that the said plunger and cam-track follower attached thereto will oscillate axially within the housing member when the camtrack member revolves. A suitable tool-holder is operatively connected to the plunger so as to .nism fortranslating rotary motion into oscillat will be superior in construction and ease of operation to any previously-disclosed method of converting rotary motion to reciprocating motion.

The present invention contemplates a tool which has a wide range of uses and can be used for burring, chamfering, slotting, cutting, filing, polishing, honing and sawing wood, metal, plastic, fiber, rubber and other materials.

It-is contemplated that the present invention can be adapted either for use in conjunction with a remote, independent or separable source of ro- 'tary power or can be used in conjunction with a power-source supported within the housing of the present invention.

With the above and other objects in view, the presentembodiment of my invention consists of a light-weight metal housing enclosing a rotatable cam-track, one end of which is adapted to be secured to the chuck or gripping surfaces of a rotating shaft or tool such as a hand-power drill, or upright bench-type power drill or to any other flexible or fixed rotating shaft or the like. Anon-rotatable, axially-movable plunger ing or reciprocating motion. The above and other objects in view will appear more fully' from the following description and drawings.

For thepurpose of illustrating the invention,

there are shown in the accompanying" drawings forms thereof which are at present preferred, al-

though it is to be understood thatthe various instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrangements and organizations of the instrumentalities as herein shown and described.

Referring to the accompanying drawings wherein like reference characters refer to like parts: 7

Figure 1 rep-resents a perspctive view of one embodiment of the present invention.

Figure 2 represents a perspective view of a second embodiment of the present invention.

Figure 3 represents a vertical cross-sectional view of the embodimentshown in Figure 1.

Figure 4 represents a front elevational view, partly in cross-section, taken generally along lines 'i l of Figure 3.

Figure 8 represents a perspective view, partly in section, showing the cam-track follower and associated parts.

Figure 9 represents a horizontal cross-sectional view of the rotating cam-track element, better to reveal the relation of cam-track to camtrack follower.

Figure 10 represents aperspective view of the cam-track follower-shoe or sled.

Referring now to the drawings, and particularly to Figures 1, 3 and 6, there is shown a housing consisting of body-member I!) which is generally cylindrical in cross-section at its rear end H and which tapers to a smaller, irregularly-v shaped front end 72. An internal cavity I3 is formed within the body It? extending from the rear end i I toa shoulder or wall l4 approximately half-way from front to rear of the body 10. An internal thread [5 is formed at the rear end of the cavity l3 so as to engage an external thread #6 formed on a reduced diameter of the front end 47.

A cavity i9 is formed in the rear end of the cap-member l8, and a small diameter passageway 29 inter-connects the cavity H! of the cap- -member [8 and the cavity I3 of the body-member It. A countersunk shoulder 2| in passageway 20, and a similar countersunk shoulder 22 in the front wall [4 of body-member ID are adapted to receive front and rear ball-bearing members 23 and 24, respectively. A second opening or passageway 25 extends forwardly from the wall 14 to the extreme front of body-member l0. Thus is provided a hOllSll'lg unit consisting of body It! and cap-member l8 having internal cavities and passageways adapted to receive rotating and oscillating members hereinafter to be described.

Journaled in the ball-bearing members 23 and 24 is a rotating cam-track housing 28 Which has a rearwardly-extending tubular axle 27 and a forwardly-extending tubular axle 33. A coupling member .28, consisting of a threaded stud 29 and a lock-nut 30, serves-to seal off the end of axle 27, and also provide a reduced-diameter extension thereof.

The locking nut 30 prevents rotation of the stud 29 with respect to the axle 27. This stud provides a suitable extension of the axle 27, of a reduced diameter, which is more readily engaged by a chuck (or other gripping surfaces) 7| of the rotary power source 72. However, it is obvious that the axle 27 (instead of stud 29) could be engaged by the chuck 7| if the jaws of the chuck opened sufficiently to permit the insertion of the axle 27 or, on the other hand, if the axle 27 was small enough to permit its ready insertion into the chuck 7|. The axle 2! is journaled within the inner race of ball bearing member 24 while the axle 33 is adapted to fit within the inner race of ball bearing member 23.

From. the above, itcan be readily seen that when a rotating force is applied to a stud 29 or axle 27, the cam-track housing member 26 is free to rotate within cavity [3 upon the ball bearing members 23 and 24.

The cam-track housing 25, in the present form a shown particularly in Figure 7, consists of a cylindrical external shell 34, a rear endplate 35 and a front end plate 33. As is shown particularly in Figure 3, the end plate 35 may be formed integrally with the axle 27, or, if desired, the axle 27 and the end plate 35 may be separate pieces suitably fastened together so that the end plate 35 will revolve when the axle 27 is turned. A shoulder or step 37, of greater diameter than the axle 27, is formed at the junction between the axle 27 and the plate 35. Thi shoulder or step 37 serves as a stop-member against which a, fan blade 38 may be seated. The fan is held securely in place against the step 37 by the inner race of the ball bearing member 24. Since the inner race of the ball bearing member 24 is press-fitted onto the shaft 27, the fan 38 is securely held in place against the step 37 and will be rotated along with the axle 27. The end plate 35 is securely held to the outer shell 34 of the cam-track housing26 by a series of screws 39. In like manner, axle 33 is secured to front end-plate 36 and to the outer shell 34. In the preferred form, the axles 21 and 33 are integral with the end-plates 35 and 36 respectively.

Between the end plates 35 and 36, and within the shell 34, a double-faced cam-track is formed as follows. A hollow cylinder 49 (havin an outside diameter equal to the inside diameter of the shell 34 and having a length somewhat less than the distance between the inside face of plate 35 and the inside face of plate 36, and having a radial thickness equal to the desired width of the cam-track) is cut into two pieces 46-a and 40--b in such a manner that the line of separation forms an endless, undulating curve around the periphery of the cylinder with an axial traverse somewhat less than the length of cylinder 40 and with one axial reversal point displaced from the other axial reversal point so as to form a generally sinusoidal curve. Vfhen these two sections 40a and 40-b are axially separated a distance A (equal to the desired height of the cam-track) the ends of the sections 46a and 46-h abut, and are adjacent to, the end plates 35 and 36 respectively. In this manner a doublefaced sinusoidal cam-track 4| is formed within the shell 34 of the cam-track housing 26 so as to provide a rotating track for a cam-follower hereinafter to be described.

Within the hollow axles 27 and 33 is journaled a slidable plunger 42 (shown in detail in Figure 8). The plunger consists of an axially-extending shaft 43 and a radially extending hollow crossbar 44.

A co-axial hole extends through one end 43a of shaft 43 from the crossbar 44 to the rear extremity thereof, which distance is slightly less than half the length of shaft 43. The other end 43b of shaft 43 is a solid shaft journaled within the axle 33. Within the hollow crossbar 44 is a bronze bearing sleeve 45 adapted to receive the shank or sleeve 46 of the cam follower sled 47 (shown in detail in Figure 10) The cam sled 47 is generally T-shaped, with the head of the T forming a circular segment having the same curvature as the cam-track 4|. The shank 46 and the head 48 are preferably formed from one piece of metal and the ends of the head 48 are tapered to points, as at 49 and 36 for a purpose hereinafter to be described.

Thus it can be seen that when the T-shaped sled 47 is journaled within the bronze bearing member 45 of the crossbar 44, an axially oscillating motion will be imparted to the shaft 43 when the cam-track housing member 26 is retated and the shaft 43 is secured against rotation but permitted to move axially.

Therefore, it is obvious that a rotary motion imparted to shaft 27 will cause the shaft 43 to oscillate back and forth a distance equal to the axial traverse of the cam-track 4 i.

As is seen in Figures 3 and 5, the front end 43-22 of shaft 43 is operatively connected to a sliding tool-holder 5!. The holder 5| is cylindrical in shape and moves axially within a bearingsleeve 52 securely fastenedwithinthe pas- .sageway '25 in the front end of the body member side of the housing 5|) which travels in a slot 54' formed in one side of passageway and sleeve 52. Thus, as shaft 43 oscillates back and forth, it causes the holding member 5| to oscillate with the same amplitude, but both the shaft 43 and the holder 5| are restrained from rotary movement by the key 53 riding in the slot 54.

The cylindrical holder 5| has a passageway 55 and a countersunk hole 55 to receive a screwthread member 51 which securely binds the shaft 43 to-the holding member 5|. The threads on the screw 51 are right-hand threads so that any torque applied to shaft 43 will tend to bind the shaft 43 and the holding member 5| more tightly together.

At the outer-end of the holding member 5|, a second larger countersunk recess 58 is formed to receive a spring-collet 59. A set-screw Eli is adapted to be turned into a V-slot til in the spring-collet 59 in such a manner that the shank 62 of a tool 63 will be firmly held within the collet 59. The set-screw serves to retain the collet 59 in the recess 58, as well as to fasten the collet to the tool 63. In this manner, the reciprocating motion of shaft 43 and holder 5| is imparted to the tool held'by the spring-collet 59.

A guide-member 64 has a shank slidably mounted in a recess 56 which is paralel to the passageway 25. The shank 65 of the guidemember 54 is held in place within the recess 66 by a set-screw Bl in such a manner that the foot 5' 68 of the guide-member 64 can be moved axially toward or away from the body member it to such a position as the user deemsmost desirable to properly guide the tool 63 when in operative position.

As previously stated, a fan 38 rotates with the cam-track housing 26, drawing air through a plurality of axial openings 69 in the body capmember l8. This blast of air is forced through the cavity [3 in the body-member l0 and is blown toward the working edge of the tool 63 through a, plurality of air ducts 1|). These air ducts 15 are so positioned within the body ill that the blast of air will cause the chips or filings removed by tool 63 to be blown away from the working surface, thereby keeping the surface free for inspection and efllcient operation at all times.

As is shown particularly in Figure 2, I may alter the shape of the cap-member |8a by extending the rear end thereof so that it engages the cover '|3a of the power drill or other prime mover '22. The front end of cover IS-a is adapted to receive the toothed projections"! formed in the rear'edge of the cap-member lit-a. The interlocking of the teeth i4 and the cover 13-0, prevents the body-member l5 and the cap-member |8a from rotating, and only a slight force "is required to be exerted by the user.

to keep the teeth I4 interlocked with the cover 13 a.

With reference to the embodiment shown in Figure 1, the cap-member l8 and the bodymember It! are guided by one hand of the user whie the grip of the drill I2 is held in the users other hand. Thus the operator can use the embodiment shown in Figure 1 to cut irregular or curved lines simply by altering the angular relation of the body-member Ill with'respect to the cover 13. The controlling force (which the in the embodiment shown in Figure '1) also'prevents the body member H) from rotating with respect to the chuck ll of the drill l2.

:In the embodiment shown in Figure 2, the cap-member |8a and thebody-member H] are locked against rotationwith respect to-the cover Therefore, although no effort need be exerted to prevent the rotationof the body-member II] with respect to the drill '32,

the entire drill and tool assembly must be turned or rotated Whenever it is desired to cut a curved or irregular line with the cutting member.

In the embodiment shown in Figure l as well as the embodiment oflFigure 2, the cap-members,

|8 and |8-a respectively; are adapted to overlie the rapidly-rotating chuok'll of the power-source H. In this manner, a shield is provided which protects the users hands from the rotating chuck and prevents his clothing from becoming ensnarled in the tool. An appropriately-placed hole 8|] permits ready insertion of a key or tool necessary to lock the chuck TI to the stud 29 or axle 2=|.

I It is'obvious that the cap-member |8-a and the cover 13 might be a single unit (or non-separably fastened together) so as to provide a unitary oscillating tool-holder which has .a self con tained power source. Other methods of permanently attaching a motor or power source to the cap-member ill-11 and the shaft 2! Will be apparent to those skilled in the art.

Similarly, the embodiment shown in Figure -1 easily may beadapt'ed for operation with a nonportable bench-supported power drill or'the like.

This'type of drill, in'its most common form, is supported with a rotating axis in a vertical direction and is usually permanently attached to .a bench or some other support. Withfthe embodiment shown in Figure 1 attached to the chuck of such a bench-supported drill, a verti- (tally-oscillating to-ol holder is provided. Since the embodiment shown in ,Figure l may be clamped against rotation by any suitable bracket fastened to the bench or to the drill-support, the vertically-oscillating toolneed not be supported by the operator, and both the operators hands will be free to handle the material being sawed or filed or otherwisetreated'by the verticallyoscillating tool.

The operation of the present invention is as follows:

With the cam-track assembly journaled within the ball bearing members 2-3 and 24 in cavity I3 and body-member l0, and with the cap-member |8.f1rmly attached to said body-member, the stud 29. on shaft 2'! is inserted into the open jaws of the chuck H of the power-source 12. Then the "jaws ofthe chuck H are securely clamped against rotation of the stud 29 in a manner well so that the tool 63 may be supported against the work in proper operating position, after which the set-screw 61 is secured against the shank user exerts to guide the path of the cutting blade I to hold the guide-member 54 against movement. With the body-member l0 securely held in one hand, the power-source I2 (securely held in the other hand) is set in motion and chuck 1| caused to rotate at high speed. This rotation is transmitted to the cam-track housing 26 and its associated elements, imparting a rapid oscil lating motion to the shaft 43, the holder member and the tool 63. The fan 38 draws air into cavity l3 through the slots 69, and forces it out through air ducts Ill, thereby blowing away all chips or filings from the cutting edge of the tool 63.

As previously described, the shaft 43 does not rotate (since the key 53 in slot 54 restrains any rotary motion) and, therefore, the sled 41' is forced to travel around the cam-track formed by the cam-track members 4||--a and 40-4). The internal cavity J5 of the cam-track housing 26 is filled with oil or other lubricant so as to permit ease in passage of the sled 4'! along the camtrack. As is best shown in Figure 9, the edges 49 and 50 of'the head 48 of the sled 41 are tapered. Thus, when the cam-track 4| is rotated past the sled 41, the lubricant is trapped between the inclined surfaces 16 and 1'! of the sled-follower 48, forcing lubricant between the surfaces of the sled-follower and the surfaces of the camtrack 4|.

The faces 16 and ll of sled 41 are opposed convex surfaces, each having a radius of curvature generally the same as the radius of curvature of the cam-track 4| at its points of reversal.

Thus, the follower can absorb the shock imposed thereon when the plunger 43 reaches the end of its axial movement and reverses direction. The head of the follower tends to plane or sled around the reversal-curve on a film of lubricant forced between the track 4| and the faces 76 and ll.

In addition, the reciprocating action of shaft 43a within the rotating axle 21 causes a pumping action and lubricant is circulated from the internal cavity 75 through the hollow shaft 46 and the hollow shaft 43-a thereby insuring that all moving parts are adequately lubricated at all times. Appropriately-placed openings 18 and 19 in sleeve 45 and shank 46 respectively, provide passages through which the lubricant can flow from shank 46 to shaft 43-a. Because of the high speed at which the cam-track housing rotates, the oil contained in the housing circulates rapidly and has a tendency to vaporize. This vaporization, plus the high-speed pumping action described above, forces oil between the shaft 43-b and the axle 33, depositin a film of oil on the bearing-sleeve 52 and the ball-bearing 23, whereby these elements are properly lubricated.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being had to theappended claims rather than to the foregoing description to indicate the scope of the invention.

Having described my invention, I claim as new and desire to protect by Letters Patent, the following:

1. A converter for changing rotary motion to reciprocating motion including a housing, a hollow cam-track member rotatably mounted within the housing and having at each Opposite end a hollow axle journaled within the housing, a reciprocable plunger within said cam-track member and having at each opposite end a shaft section axially slideably mounted in one of said hollow axles, said cam-track member having an endless cam-groove in its inner face describing a path which travels axially from one axially extreme position to another and back again in a revolution of the member, a cam-follower journaled on said plunger, extending therefrom gena hollow axle journaled within the housing, a reciprocable plunger within said cam-track member and having at each opposite end a shaft section axially slideably mounted in one of said hollow axles, said cam track member having an endless cam-grcove in'its inner face describing a path which travels axially from one axially extreme position to another and back again in a revolution of the member, a cam-follower pivot member journaled on said plunger and slideable in said cam-groove for oscillation to and fro about its journal as it travels in said cam-groove, said cam-follower pivot member having oppositely curved convex cam-groove engaging faces which intersect each other near the opposite ends of said member, the radius of curvature of said faces being substantially the same as that of the camgroove at the axially extreme ends thereof, and a key operatively interposed between said plunger and the housing to prevent rotation of the plunger relatively to the housing.

3. A converter for changing rotary-motion to reciprocating motion including a housing, a hollow cam-track member rotatably mounted within the housing and having at each opposite end a hollow axle journaled Within the housing, a reciprocable plunger within said cam-track member and having at each opposite end a shaft section axially slideably mounted in one of said hollow axles, said cam-track member having an endless cam-grove in its inner face describing a path which travels axially from one axially extreme position to another and back again in a revolution of the member, a hollow cross-bar journaled in the plunger, extending substantially radially therefrom and having at its outer end a cam-follower pivot member having a hollow bore communicating with the hollow of the cross-bar and positioned in said cam-groove for oscillation to and fro as the cam-track member rotates, and a key operatively interposed between the plunger and the housing to prevent rotation of the plunger relatively to the housing, said plunger having an internal passage communicating with the hollow of the cross-bar for conducting lubricant to the cam-follower pivot member and cam-groove.

4. A converter for changing rotary motion to reciprocating motion including a housing, a hollow cam-track member rotatably mounted within the housing and having at each opposite end a hollow axle journaled Within the housing, a reciprocable plunger within said cam-track member and having at each opposite end a shaft section axially slideably mounted in one of, said hollow axles, said cam-track member having an endless cam-groove in its inner face describing a path which travels axially from one axially extreme position to another and back again in a revolution of the member, a hollow cross-bar journaled in the plunger, extending substantially radially therefrom and having at its outer end a cam-follower pivot member having a hollow bore communicating with the hollow of the cross bar and positioned in said cam-grove for oscillation to and fro as the cam-track member rotates, said cam-follower pivot member having oppositely curved convex cam-groove engaging faces which intersect each other near the opposite ends of said member, the radius of curvature of said faces being substantially the same as that of the cam-groove at the axially'extreme ends thereof, and a key operatively interposed between the plunger and the housing to prevent rotation of the plunger relatively to the" housing, said plunger having an internal passage communicating with the hollow of the cross-bar for conducting lubricant to the cam-follower pivot member and cam-groove.

HENRY F. VACHE'. 15

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Rogers July 7, 1857 Booth Nov. 3, 1891 Fast Apr. 1, 1919 Wodack et a1. Apr. 9, 1929 Major Apr. 14, 1931 Farkas July 12, 1932 Simmons June 28, 1938 Sheerer Feb, 24, 1942 

